cgroup: remove unused variable

/scratch/sfr/next/kernel/cgroup.c: In function 'cgroup_tasks_start':
/scratch/sfr/next/kernel/cgroup.c:2107: warning: unused variable 'i'

Introduced in commit cc31edce "cgroups:
convert tasks file to use a seq_file with shared pid array".
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/cgroup.c

@@ -2104,7 +2104,7 @@ static void *cgroup_tasks_start(struct seq_file *s, loff_t *pos)
 	down_read(&cgrp->pids_mutex);
 	if (pid) {
 		int end = cgrp->pids_length;
-		int i;
+
 		while (index < end) {
 			int mid = (index + end) / 2;
 			if (cgrp->tasks_pids[mid] == pid) {